Air compressor



May

2553 .4 ZHSSV 95255457 22 A 55 v525| B. s. AIKMAN 2,319,911

AIR COMPRESSOR INVENTOR- BURTONSAIKMAN www fm ATTORNEY May 25, 1943. 1 a. s. AIKMAN 2,319,911

AIR COMPRESSOR Filed Jan. 2a; 195s e sheets-sheet 2 iw "uw Y...ml-mug' y l "l 'IZD 122 l' ZJTO 12| ff los/1 INVENTOR BURTON SAIKMAN May 25, 1943. a. s. AIKMAN AIR COMPRESSOR Filed Jan. 28, 1939 6 sheets-Sheet 5 \l v// 4 w v N M m f V .w MA

s mm um ATTORNEY May 25, 1943. B. s. AIKMAN 2,319,911

AIR COMPRESSOR Filed Jan. 28. 1939 6 Sheets-Sheet 4 2@ es is@ g 209, 208 206 20620@ lo lsl [f-ZOO INVENTOR BURTONSAlKMA ATTORNEY May 25 1943- i B. s. AIKMAN 2,319,911

AIR 'COMPRESSOR l Filed Jan. 28, 1939 6 Sheets-Sheet 5 BY y am, im

ATTORNEY May 25, `1943- B. s. AIKMAN 2,319,911

AIR COMPRESSOR Filed Jan. 28, 1959 6 SheetsPSheet 6 l' C'dranacoas Maia/'icl a HO HO @m -l VEN@ -lllllllllll Caf-gnaceoz/s haie/afa 33@ 332- iNvENToR @e7 BURTON sAlKMAN Patented May 25, 1943 Am COMPRESSOR Burton S. Aikman, Wilkinsburg, Pa., assigner to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application January 28, 1939, Serial No. 253,378 7 Claims. I (Cl. 2311-159) This invention relates to fluid compressors, and more particularly to a compressor having oscillating pistons orvanes for compressing air or other fluid.

In designing a compressor of the conventional reciprocating piston type, it has been found difficult to produce a machine which occupies only a relatively small space and which at the same time is adapted for the high speed operationnecessary to insure maximum capacity, because of problems including those of providing for maximum volumetric efficiency and proper cooling'of the compacted parts of such a compressor, as well as structural problems such as those of providing dependable lubricating means and of balancing or minimizing load on the bearings and other operating elements.

One object of the present invention is to provide an ecient high speed compressor of small dimensions, the novel construction and arrangement of the parts of which are such asto obviate the above diiculties.

Another object of the invention is to provide a high speed compressor of sturdy and inexpensive design, comprising a casing having arcuate compression chambers within which balanced fluid `compressing pistons or vanes are operatively mounted, and means including a central shaft for oscillating the vanes for effecting a continuous flow of fluid under pressure by way of suitable valves associated with each chamber.

It is a further object of the invention to provide a compressor ofgthe above type adapted to be provided with fluid compressing'vanes and sealing elements formed of ascii-lubricating substance, preferably asolid carboriaceous material, so that fluid lubricant is not required in the portion of the` compressor through which the air or other fluid is passed during the compressing operation.

A still further object is to provide an eilicient air cooled compressor iii which the various members and operating parts are so constructed and arranged as to occupy relatively small space. 5

Other objects and advantages of the invention will appear in the following more detailed description thereof, taken in connection with Fig. 3 is a sectional view taken substantially along the line 3-3 of Fig. 1;

Fig. 4 is a sectional view taken along the line I-l of Fig. 1;

Fig. 5 is a fragmentary plan view of another form of oscillating drive mechanism for a com-v pressor embodying my invention;

Fig. 6 is a sectional plan' view, similar to that in Fig. 3, but showing a different embodiment of the invention;

Fig. 7 is a sectional plan view of one of the fluid compressing vane devices shown in Fig. 6;

Fig. 8 is an elevational view, mainly in section, of the compressor shown in Fig. 6;

, Fig. 9 is a fragmentary elevational view, main- 1y in section, illustrating another method of cooling a compressor embodying the invention;

Fig. 10 is a sectional view of the compressing portion of a compressor constructed in accordance with still another form of the invention;

Fig. 11 is a, sectional view taken along the line lI-.Il of Fig. 10:

Fig. 12 is a sectional view taken along the line l2-.I2 of Fig. 10; and

Fig; 134 is a fragmentary sectional view showing one of the uid compressing vanes of the compressor shown in Fig.Y 10 automatically adjusted for wear.

Description of embodiment shown in Figs. 1 to 5 As shown in Fig. l of the drawings, the invention may be embodied in an equipment comprising an oscillating compressor l5, a gear housing I6 adapted to carry the compressor, a base portion I1 supporting the gear housing, and adriving motor I8 mounted on the base portion.

According to my invention, the compressor I5 is of novel construction and has a mode of operation entirely unlike that of the conventional compressor, in that it embodies, among other features, a pair of oppositely disposed self-lubricating vanes which are adapted to be oscillated by means of a single shaft for compressing fluid within separate arcuate compression chambers. The compressor l5 comprises a cylindrical casing 20Uprovided with exterior annular cooling fins I9 and having formed at the inner end thereof an annular flange portion 2|, which is adapted for sealing engagement with a complementary flange portion 22 formed on the gear housing i6 vand is secured thereto by means of bolts 23. The

bearing portion 26 carried by the gear housing |6 and extending from a web portion 21 formed integrally within the flange portion 22. A` cylindrical bushing 29 is fitted within the bearing portion 26 and has journaled therein a compressor shaft 30, an outer portion of which extends coaxially within the'` bore 25 of the compressor casing. The outer end of the shaft 30 carries a substantially circular drum member 32, which has a longitudinal bore for receiving the shaft 38 and is secured thereto by means of a key 33.

The drum member 32 has two longitudinal channels 35 formed therein diametrically opposite each other and equally spaced from the shaft 30, as is best'shown in Fig. 3 of the drawings. Slidably mounted in each of the channels is one of a rpair of fluid compressing abutments or vane members 36, both of which extend outwardly of the drum member 32 and have suit- .ably curved bearing surfaces 36a disposed in sliding engagement with the wall of the bore 25. One or more springs. 38 are interposed between the inner end of each vane member 36 and the wall of the channel 35 for urging the vane member outwardly.

Each of the vane members 36 comprises a substantially rectangular block preferably made of self-lubricating non-metallic material, such as carbon or a suitable carbonaceous composition, and is providedv with'reenforcing plates 40 secured at opposite sides thereof 'by means of transverse rivets 4|. that the carbonaceous material of which the vanemembers 36 may be made is of such a texture as will receive a smooth or polished surface such as the bearing surfaces 36a., and is adapted to have low friction characteristics such as will permit operation of the vanes 36 in sliding contact with the interior wallat the casing 20 without requiring the supply of fluid lubricant.

The self-lubricating vane members 36 are provided with terminal sealing faces and are adapted to be interposed between two annular end plate elements 44 and 45, which, as shown in Fig. 1, are disposed concentrically of the shaft 30 and are respectively secured by means of bolts 46 and 41 to a pair of matched semicircular valve members 48 and 49 that are spaced on opposite sides of and in sliding engagement with the drum member 32. Within the flange portion 2| flat seat portions 48a and 49a, respectively, which are aligned for sealing engagement with the adjacent areas of the reenforcing plates 40 of said vane members. It will be observed that the drum member 32 and vane members 36 carried thereby are adapted to have a lost motion or relative movement with respect to the associated valve members 48 and 49, and that the seat portions 48a and 49a of the latter are so spaced on opposite sides of each corresponding vane member 'as to cause one or the other of said seat portions to be held in seating engagement with the vane memberl while the other seating portion is maintained out of engagement therewith. As hereinafter more fully explained, the valve members 48 and 49 are adapted to control the inlet supply of air or uid to the compressor.

Formed on diametrically opposite sides of the casing 20 are two valve box portions 68 and- A or' members 65 and 66, which are disposed longi- It should be ndertsood tudinally of the compressor casing 28 and have suitably curved sealingv surfaces 65a. and 66a adapted to. be held in sliding engagement with the outer surface o f the arcuate valve member A, 49 under the pressure of coil springs 61 which 'are interposed-between the respective members 65 and 66 and the -wall of the chamber 62. One

^ or more coil springs 69 may be interposed beof the casing 20 are formed a pair of annular l recesses 5| adapted to receive two arcuate sealing members 52, which are preferably formed ofA a self-lubricatingcarbonaceous material similar to that of the vane member 36. The sealing members 52 are disposed concentrically of the shaft 30, andgare yieldingly supported in sliding engagement with an annular ange portion 44a of the sealing plate element 44 by means of springs 53 which are mounted in suitable seats formed in the casing.

Similarly, an annular ange portion 54 formed on the outer end of the casing 20 is provided with recesses 55 containing arcuatesealing memsemi-circular valve members 48 and 49, which .valve members are provided at each end with tween the valve members and 66 for urging them apart and into seating'engagement with longitudinally disposed valve seat members1l and 12, respectively, which seat members may be secured to the box portion 60 by any suitable means such as screws 13.

Similarly, the discharge chamber 63 has y mounted therein a pair of discharge valve members and 86, which, like the members 65 and 66 are preferably formed of self-lubricating carbonaceous material and have longitudinal sealing surfaces 85a and 86a bearing against the outer surface of the arcuate valve member 48 under the force of coil springs 81. One or more coil springs 89 are interposed between the valve members 85 and 86 for urging them into seating engagement with seat membersv 9| and.92, respectively, which are secured to the casing `by 'means of screws 93.

It will be understood that the terminal end surfaces of the respective discharge valve members 65, 66, 85 and 86 are suitably formed for sliding and sealing engagement with the. inner'- surfaces of the sealing plate elements 44 and 45 v.

shown in Fig. l. It will also be observed that the two pairs of discharge valve members just referred to constitute terminal walls for two arcuatecompression chambers indicated generally by the characters 96 and 91, each of which compression chambers is adapted to be traversed by oneof the uid compressing vane members 36 during'operation of the compressor as hereinafterv explained.

As shown in Fig. 1 of the. drawings, air or other uidto be compressed is admitted to the compression. chamber by way of communications including an opening |00 formed in the annular member 45, a. plurality of passages |0| formed in the -drum member 32, and arcuate passageways |02 formed intermediate the drum member and the adjacent valve members 48 and 49. Communication from the passageways |02 to the two screen |05 is mounted outwardly of the open end of the passage for preventing access of foreign matter to the compressor.

Referring to Figs. 1 and 2, within the gear housing I6 is provided an oscillating drive mechanism operative to actuate the compressor shaft 30 and associated elements with an alternately reversing rotary motion, which mechanism is contained within a chamber formed in the housing and entirely separated from operating parts of the compressor yI5 by the web portion 21. Rotatively mounted in the upper part of the chamber |05 is a pinion |01, which is keyed or otherwise connected to the drive shaft of the motor device I8, and has a supporting bearing portion |08 journaled in a bushing |09 carried by an end 0f a compressor shaft 30. that extends into the chamber |05. lThe pinion |01 is provided with herringbone teeth adapted to mesh with similarly foJned teeth of a gear IIO, which has acentral sleeve portion 'III journaled on a horizontally disposed stud I I2 having one end mounted in a bore II3 formed in the housing I6 and the other end secured by means of a pin I I4 in a cap member I I5, which is secured to the housing by bolts I I6. Formed integrally with or suitably secured to the cylindrical portion III of the gear is an eccentric disc II8, which is disposed beneath the end of the compressor shaft 30 extending into the chamber |05. A

As is best shown in Fig. 2 of the drawings, strap element |20 is journaled on the eccentric disc I I8, which strap element has formed thereon an upwardly extending rack portion |2I having a plurality of teeth |22. A semi-circular pinion |23 is formed on or suitably secured to the end of the compressor shaft 30 within the chamber |05 and is provided with teeth |24 which are adapted to mesh with the teeth |22 of the rack portion |2I under the force of a tension spring |25, which is connected to a lug I 26 formed on the rack portion and to a lug |21 provided on the wall of the housing I6.

It will be understood that the rack portion I2I and pinion |23 associated therewith are so constructed and arranged that upon each revolution of the eccentric disc II8, the strap |20 and rack portion I2I thereof are actuated to effect rotation of the pinion |23 and the compressor shaft 30 in one direction through an angle equal to that traversed by the fluid compressing varies 36 as shown in Fig. 3. during one compression stroke thereof as hereinafter explained, followed by returned rotation of said compressor shaft 30 in the reverse direction and through the same angle.

In order to provide splash lubrication for the oscillating drive mechanism just described. the chamber |05 within the housing I6 is adapted to contain a supply of lubricant |30 within the path of the teeth of the gear I I0, which is thus adapted in operation to ,carry lubricant upwardly and to propel it against the lupper walls of the chamber.

A trough I3I is formed on the web portion 21 for receiving a portion of the lubricant thrown from the gear IIO, from which trough the lubricant ispermitted to ow through a passage |32 provided in the conical portion 26 and bushing 29 to the bearing surface of the compressor shaft 30. .In order to prevent lubricant from leaking past the shaft 30 into other portions of the compressor, a return flow passage |33 is formed in the lower portion of the conical portion 26, which passage communicates with the chamber |05 as shown in Fig. 1. Oil ducts |35 are formed in the cylindrical portion III for admitting lubricant to the bearing surface of stud II2.

Operation of embodiment shown in Fig. 1

When supplied with electric current the driving motor I8 is operated in the usual manner to rotate the pinion |01, which in turn effects rotation of the gear IIO and the eccentric disc I I8 connected thereto. As hereinbefore explained the rotation of the eccentric disc II8 is effective through the medium of the strap |20 and rack portion I2I to effect alternately reversing rotation of the pinion I 23 and compressor shaft 30 through a predetermined angle.4

Referring to Fig. 3 and assuming that the vane members 36 and associated elements are initially positioned as therein shown. it will be observed that the valve seat portion 49a within the chamber 96 and the valve seat portion 49a within the chamber 91 are both positioned out of engagement with the corresponding plates 40 of the vane members, so that air is free to flow from the atmosphere by way of the passage I 00 (see Fig; 1) and passages IOI and |02 to the compression chambers 96 and 91. At the same time, the discharge valve members 65, 66, 85 and 86 are held in their respective seated positions.

If the compressor shaft30 and the drum member 32 are now rotated in a clockwise direction, as viewed in Fig. 3, the vane members 3'6 are initially moved in the same direction toward the valve seat portion 48a within chamber 96 and valve seat portion 49a within chamber 91, respectively, it being understood that the valve members 48 and 49 together with the sealing plate members 44 and 45 shown in Fig. 1 are held stationary due to friction and inertia during this first period of the compression stroke. It will also be noted that in thus moving, the vane member 36 within the chamber 96 is carried away from the valve seat portion 49a, while similarly the vane member 36 in chamber 91 is moved out of engagement with the valve seat portion 48a.

As the leading faces of the vane members 36 are thus brought against the adjacent valve seat portions, and the members are further rotated in a clockwise direction, the valve members 48 and 49 and the sealing plate members 44 and 45 are carried in the same direction, While fluid is compressed within the portions of the complession chambers 96 and 91 at the respective leading sides of the vane members.

Fluid thus compressed in the compression chamber 96 at the right of the vane member 36, as viewed in Fig. 3, acts on the exposed surface of the `discharge valve member 8,5 and forces the valve member downwardly and away from the valve seat member 9| against the forceof the spring 89, whereupon fluid under pressure is discharged from the compression chamber 96 to the valve chamber 63 and' thence through the conduit 63a to the usual receiving reservoir. At the same time, air or fluid to be compressed is drawn into the portion of the chamber 96 to the left of the Vane member 36, i. e., on the trailing side thereof', by way of theinlctpassages IOI and |02, and past the unseated seat portion 49a of the valve element 49.

In like manner fluid under pressure in the 30 yand rotation thereof in a counterclockwise di- `@repression chamber s1. at the leading side of the lower vane member 36 is effective to force the discharge valve member 66 away from the seat 12 for permitting discharge of fluid under pressure from the chamber 91 through the valve chamber 62 and conduit 62a 'to the reservoir, while uid is admitted to the portion of the chamber 91 at the trailing side of the vane member 36 by way of the passages |0| and |02 and past the unseated portion 48a of the inlet valve When the vane members 36 have thus been rotated through the angle limiting the extent of the stroke in one direction, the compressor shaft nd drum member 32 are brought to a stop rection is immediately begun by operation of the oscillating drive mechanism as hereinbefore 'explained. As the compression vane members 36 are thus' carried in a counterclockwise direction, fluid is again compressed within the chambers 96 and 91 at the leading sides of the vane members, it being understood of course that initial counterclockwise movement thereof again effects seating of the valve seat portion 49a. within chamber 9'6 and of'the valve seat portion 48a in chamber 91. Fluid compressed within the chamber 96 is this time discharged therefrom past the discharge valve member which has meanwhile been moved away from the valve seat member 1|, while iiuid. under pressure is discharged from the chamber 91 past the unseated discharge valve member 86 and thence to the receiving reser- Voir.

It will thus be apparent that, as the above explained cycle of oscillation of the compressing vanes 36 is repeated by continued operation of the associated driving motor and gear mechanism the compressor I5 is :operated to effect a substantially constant supDly of uid under pressure by way of the conduits 62a and 63a to the receiving reservoir. It will further be noted that the compressor driving mechanism is operative to oscillate the compressing vanes through relatively long strokes, so that the respective vane members may be provided with smaller compression areas than would otherwise be the case in providing for the required displacement, thereby minimizing load on the compressor driving mechanism.

In Fig. 5 ofthe drawings there is disclosed a different form of the oscillating drive mechanism which may be substituted for that shown in Fig. 2 as a means for converting unidirectional rotary motor of the gear and associated cylindrical portion into. oscillating motion or alternately r reversingrotation ofthe compressor shaft 30. As shown in Fig. 5, vthe mechanism includes anl stud ||2 in the manner hereinaboveA explained,

,the strap member |4| andarm portion |'42 thereof will be reciprocatad for operating the pin |43 and crank |44 to oscillate the compressor shaft 30 through an angle determined by the required extent ofmovement of the fluid compressing vanes as already explained.

Description in embodiment shown in Fins. 6 to 8 A compressor embodying my invention in a different form is illustrated in Figs. 6 to 8, inclusive, which compressor, although having substantially the same mode of operation as that al- 'Ihe compressor |50 comprises a cylindrical casing having a plurality of exterior heat radiating ns |6| and provided with an interior bore |62, as shown in Fig. 6. The casing |60 is secured by suitable means, not shown, to a casing section |63 having la flange portion |64 which is secured to a complementary iiange portion |65 of the-housing |5| by means o f' bolts |66. The ange portion |65 of the housing isI formed around an opening |61, which is adapted to be closed by a centrally disposed conical portion |68 formed on the casing section |63 and extending partly into the bore Within the casing |60, as best shownin Fig. 8.

The hollow conical portion |68 is fitted with a longitudinally disposedA bushing |10 in4 which is journaled a compressor shaft 12 having one end thereof disposed concentrically within the bore of the casing |60 and carrying at the inner end also formed in the conical portion |68 for providing communication through which excess oil may ow from the bearing of .the compressorl shaft |12 fto the chamber |52.

Concentrically disposed within the bore |62 of :the compressor casing |60 is a hollow drum memwith a. longitudinal bore and tted on the compressor shaft |12. The hub portion '|84 may be secured to theshaft |12 by any suitable means I such -as a key- |85. Two diametrically opposite socket ,portions |86 are 'formed on the drum member |83, each of which is provided lwith a longitudinal recess |90 adapted'to receive one of a pair of self-lubricating vane devices |9I, as shown in Fig. 6. The outer portions of the vane devices |9| are vadapted to extend into lsliding engagement with the wall of the bore |62 under' to .the adjacent socket portion |86 of the drum' member forpreventing misalignment of the vane devices.

Referring to Fig.`7, each of the vane devices '|9I comprises 'a section 200 haiinga pair` of tongues 20| extending `longitudinally therefrom and a section 202 having spaced grooves 203 into which the tongues are adapted to be fitted,

so that thesections 200 and 202 when assembled are relatively movable toward and away from each other. Mounted in a cavity 205 formed cen- -rtrally within the sections 200 and 202 is a coil spring 206 which is adapted to urge the sections outwardly for insuring sealing engagement of the end surfaces 201 and 208 of the respective sections with end Walls provided for closing the bore |62 in the compressor casing as hereinafter more fully explained. A rectangular sealing piece 209 may be inserted in a suitable groove formed in the outer sealing surface 2| 0 of the assembled vane device for preventing yleakage of fiuid under pressure between said surface and the walls of the bore |62. Referring to Fig. 6, .it will be noted that leakage of fluid past the tongue 20| of the vane devices |9| is prevented by reason of Ithe overlapping end portions of the respective guide plates |95. It should be understood that the sections 200 and 202 of each of the vane devices |9| are adapted to be formed of the same self-lubricating carbonaceous material -as that of which the vane members 36 of the embodimentshown in Fig. 3 may be made, so that supply of oil or other lubricant to the compressor |50 will not be necessary.

Formed laterally on the casing |60 of the compressor lare la side portion 2|4 having an upper valve chamber 2|5, a lower valve chamber 2|6 and a central guide groove 2|1, anda similar side portion 220 disposed opposite the portion 2 |4 `and having formed therein upper and lower valve chambers 22| and 222 and a central guide groove 223, which is ydisposed ldiametric-ally opposi-te the groove 2|1 with respect to the shaft |12 of the compressor. A sealing block 225 is slidably mounted in the groove 2|1 and has Aa sealing surface 226 adapted. to be held in sliding-engagement with the drum member |83 under the-pressure of a coil spring 221 which is interposed between the block member and the wall of the groove 2|1. The block 225 is further supported and guided by a pair of guide members 229 and 230, which are mounted in the side portion 2|4 above and below the block byv suitable means such as bolts l23| and 232, respectively. rIhe sealing block 225 and both guide members 229 and 230 are preferably formed of self-lubricating carbonaceous material as already described.

Similarly, a sealing block 235 is -slidably mounted within the guide groove 223 between a pair 0f gui-de members 236 |and 231, and is urged into sliding eng-agement with the surface of the drum member |83 under the pressure of a coil spring 238.v The guide members 236 and 231 may be secured in place by suitable means `such as bolts 239 and 240.

It will thu-s be apparent that the space between the wall of the bore |62 in the casing |60 of the compressor and the movable drum member |83 is divided by the oppositely disposed sealing blocks 225 and 235 into two Icompression -chambers indicated generally at 244 and 245, and that the respective vane devices |9| are each disposed within one of the cimpression chambers for compressing fluid as hereinafter explained.

As shown in Fig. 8 of rthedrawings, a cover plate member 245 is secured to the outer end of the casing by means of bolts 25|, and is provided with a central opening 246 aboveand below which are formed suitable recesses containing an arcuate sealing member 241 and a similar member 248, respectively, both of which may be made of the carbonaceous material herelnbefore described. The sealing members 241 and 248 are not shown in detail in the drawings, but it will be readily understood that each of said members is arranged concentrically of the compressor shaft |12 and is adapted to prevent leakage of fluid under pressure past the adjacent end surface of the corresponding vane device |9|. Similar arcuate sealing -members 249 and 250 are mounted in recesses formed in lthe casing section |63 and are maintained in sliding engagement with the opposite end faces' of the respective vane devices I9I. K

Inlet valve portions 252 and 253 are formed on the casing section |63 and are adapted to contain similar inlet valve mechanisms for controlling the admission of air or other uid to the respective compression chambers. As shown in Fig. 8 of the drawings, the inlet valve portion 252 has formed therein a valve chamber 255 containing a valve member 256 which is normally urged into seating engagement with a seat 251 under the force of a coil spring 258 and is adapted to control iiow of fiuid by way of an inlet opening 259 to the compression chamber 244. The valve mechanism within the lower valve portion 253 is substantially the same as that just described, and is accordingly not shown in detail.

As is indicated in Fig. 6 of the drawings, the inlet valve portions 252 and 253 are disposed substantially along a vertical center line of the compressor casing |60, and it Will be understood that the valve mechanisms therein are adapted to control communication with the compression chambers 244 and 245 by way of suitable ports 260 and 26| opening into the 4respective chambers midway of the ends thereof. Each of the ports 260 and 26| is thus adapted to be uncovered by the corresponding vane device |9| as it passes the adapted to close the inlet valve ports upon traversing substantially one-half the distance through which they are operated, so that the unproductive work or energy otherwise required for compressing fluid within the inlet valve chambers and ports is reduced to a minimum.

Referring again to Fig. 6 of the drawings, a discharge valve disc 265 is disposed in the valve chamber 2 I5 and is urged toward seated position by a coil spring 266 for controlling communication from the compression chamber 244 through a port 261 to the valve chamber 2|5. The valve chamber 2|5 communicates by way of a passage 269 formed in the portion 2|4 of the casing with the lower valve chamber 2I6 therein, which lower valve chamber is likewise provided with a valve disc 21| normally held inseated position by a spring 212 for controlling communication to the valve chamber from the compression chamber 245 by way of a port 213.

The valve chamber 2 I6 is in turn connected by way of a passage 214 with the valve chamber 222, which together with the valve chamber 22| communicates by way of a passage 215 and a discharge conduit 216 with the usual receiving reser- 222 are valve discs 218 and 219, respectively, which are urged toward their seated positions by springs 280 and 28|. The valve disc 218 controls communication from the compression chamber 244 through a port 282-to the valve chamber 22|,

while the valve disc 219 controls communication,

from the lower compression chamber 245 through a port 284 to the valve chamber 222. r

In the present embodiment of my invention forced draft cooling means are provided for conducting a current of air through suitable communications formed within the compressor casing to augment the cooling effect provided by the exterior cooling ns I6 As is best shown in Fig. 8 of the drawings, the compressor shaft |12 is provided with a longitudinal bore 285, through which extends a rotary shaft 288 having an enlarged inner end 289 secured to the shaft |8a of the driving motor, and carrying on the outer end a fan 290 within the opening 246 of the cover plate 245. The enlarged end 289 of the shaft is provided with a threaded bore 29| adapted to receive a threaded end 292 of the shaft |8a, and is journaled in a bushing 293 mounted-within the end |13 of the compressor shaft |12, sothat the fan shaft 288 is thus adapted to be rotated constantly in one direction by the driving motor while the compressor shaft |12 is oscillated in periodically reversing directions as already explained. An oil duct 295 is formed in the portion |13 of the compressor shaft for admitting oil to the portion 289 of the fan shaft within the bushing 293. The outer end of the fan shaft 288 is journaled in a ball bearing assembly 291 which is carried by the hub portion |84 of the drum member.

The fan 290 is thus adapted to be operated to force a draft of air through the opening 246 in the plate member 245 and thence through the passageway formed within the drum member |83 and indicated at 300, and an annular opening 30| formed inthe casing section |63, as .indicated by the arrows in Fig. 8.

Operation of embodiment shown in, Figs. 6 to 8 Detailed description of the operation of the compressor constructed according to the present embodiment is not deemed necessary, since thel principle of operation is the same as that already described in connection with the rst embodiment. In operation, the driving motor |8 func tions through the medium of the shaft |8a to rotate the fan shaft 288 and fan 290 while the pinion |01 and gear ||0 are at the same time operated to effect alternately reversing rotation or oscillation of the compressor shaft |12. The two vane devices |9| are thereby operated by the compressor shaft |12 through the respective compression chambers 244 and 245 for compress- -ing uid.

Referring to 'Fig` 6 of the drawings, and assum- 8 ing that the fluid compressingvanes |91 are initially positioned as shown, upon rotation f the shaft |12, the dru'm member |83 and the vane devices in a clockwise directions fluid is compressed in the chambers 244 and 245 in advance of the respective vane devices. Fluid under presi sure is thereby discharged from the chamber 244 by way of the port 282, past the unseated discharge valve member 218, and through the chamber 22|-and passage 215 to the pipe 216, while iiuid under pressure is similarly discharged from the chamber 245 through the port 213, past the discharge valve member 21| and through chamvoir. Disposed in the valve chambers 22| and Y bei` 2|6, passage 214 and chamber 222 to the passage 215. -At the same time, a partial vacuum is created in the portions of the compression chambers 244 and 2,45 rearwardly of the vane devices |9|, until each vane device overpasses the corresponding inlet port 260 or 26|, whereupon the inlet valve devices contained in the valve portions 252 and 253 are operated to admit air from the atmosphere to both compression chambers in preparation for the subsequent return stroke of the vane devices.

Upon completion of the clockwise stroke of the vane devices |9l, the reciprocating drive mechanism is operated in the manner liereinbefore explained to rotate the shaft |12 and the vane devices in the reverse direction, at which time the discharge valve elements 218 and 21| are of course returned to their seated positions by the spring 280 and 212, while the inlet valve mechanisms likewise assume their closed positions. When the compressor shaft |12, drum member |83 and vane devices |9| are thus turned in a counterclockwise direction, fluid under pressure is this time forced from the chamber 244 through the port 261, past the discharge valve element 265, and through chamber 2|5, passage 289, chamber 2|6, passage 214 and chamber 222 to the passage 215, while uid under pressure is also forced from the chamber 245 by way of the port 284 and chamber 2,22 to the passage 215. It will be understood that the passage 215 is sufficiently large to permit uid under pressure in the valve chamber 222 to flow therefrom to the receiving reservoir at such a rate as to prevent undesired build up of substantial back pressure on the valve disc 219 which might otherwise tend to oppose unseating of that dise under the pressure of fluid in the port 284. When the vane devices |9| are thus moved in a counterclockwise direction past the inlet port 260 and 26|, atmospheric air is again admitted to the portion of each chamber at the trailing sides of the respective vane members as already explained.

Embodiment shown in Fig. 9

A compressor having a design similar to that shown in Fig. 8, may if desired be provided with forced draft cooling means of somewhat different form, as shown in Fig. 9 of the' drawings. According to this form of the invention there is provided a compressor 305 adapted to be mounted on'the gear housing |51 and operatively connected to the drive shaft |8a of the motor` 8 through the medium of the usual gears |01 and ||0, together with the oscillating drive mechanism already described. The compressor 305 may be of substantially the same construction as that shown in Fig. 8 and will be briey described for the purpose of disclosing the cooling features thereof not included in the other embodiment just referred to.

The compressor 305 comprises a casing 306 having formed therein suitable compression chambers adapted to have uid compressing vanes 301 mounted therein, which vanes are carried by a drum member 308 that is secured to a compressor shaft 309vv journaled in the casing. The compressor shaft 309 is, like the shaft |12 shown in Fig. 8, operative by the oscillating drive mechanism contained in the housing l5! to operate the compressor vanes 301 to compress uid in the .manner hereinbefore explained. The drum member 308 includes a hub portion 3|-0 secured to the peripheral portion of the member by spaced web portions 3| l, which extend between passageways 312. Formed on the interior. wall of the drum member 308 are longitudinally disposed radiating fins .3-13. The passageways 312 of the drum member are at one end adapted for communication with the atmosphereby way of an annular opening 315 formed in the casing section intermediate the compressor 305 and the lgear housing 151, and at the other end communioate with an opening 3 I 6 provided in the outer end of the casing 306. A plurality of radiating fins 311 are formed on the wall of the opening y end of the cover member 320 extends beyond the casing member 306 and has formed 'therein a circular opening 324, within which is disposed a fan 325 that is secured to a rotary shaft 326 operatively connected to the driving motor shaft 18a by means similar to that associated with thel shaft 288 shown in Fig. 8. It will be apparent that the blades'of the fan 325 are long enough to extend across substantially the full area of the outer end of the casing 306.

In operation, while the fluid compressing vanes 301 are oscillatedin the usual manner for compressing luid through the medium of the compressor shaft 309, the fan shaft 326 is constantly rotated in one direction for operating the fan 325 to draw atmospheric air through the opening 315, openings 312 in the drum member 308, opening 316 in the casing 306 and outwardly by way of the opening 324 in the cover member 320. At4 the same time atmospheric air is also drawn through the louvers 323 in the cover member and passes over the ns 319 andV outwardly through the opening 324. It will be apparent that heat of compression radiated from the comsides of the casing are two arcuate depressions or channels 341 and 342, at the margins of which are mounted pairs of parallel guide members 343 and 344, respectively.,

The guide members 343 together with the channel 341 provide a concave sealing surface adapted to receive a substantially cylindrical sealing device 346, which is rotatably mounted on a ylongitudinally disposed pin 341 extending between the guide members. As shown in Fig. 10', the outer curved surface of the sealing device 346 is adapted for sealing engagement with the channel 341 and associated guide members 343, and is provided with a relatively flat portion adjacent the drum member 335 which has formed V thereon a sealing surface 348 adapted for sliding pressor by means of the fins 319, and also by the interior ns 313 and 311, will be. rapidly carried away from the compressor, so that the compressor will be sufficiently cooled at all times.

Description of embodiment shown in. Figs. 10

Illustrated in Figs. 10 to 13, inclusive, is a fluid' compressor of the oscillating piston or vane type embodying features of the invention in another form. In this embodiment of the invention, there is provided a iluid compressor indicated generally at 330, which will be understood to correspond to the compressor 15 shown in Fig. 3 and the compressor 150 shown in Fig. 6. It is not deemed necessary to provide detailed illustration of the compressor 330 in association with an os- .cillating driving means, since the construction.

engagement with the drum member. l

As is best shown in Fig. 12 of the drawings, the sealing device 346 is of two piece construction, and comprises a pair of elements 350 and 351 made of the self-lubricating carbonaceous material hereinbefore described and adapted to be adjustably interlocked together, the element 350 having a transverse groove 352 adapted to.

receive a tongue portion 353 of the element 351. The elements 350 and 35| are provided with interior bores within which are mountedA coil springs 355 which are adapted to urge the elements apart and into sealing engagement with circular end plate members 358 and 359, respectively, which lare concentrically 'mounted within the casing 331 and are supported in part by the Din 341. It will be noted that the pin 341 has a head portion 341a in engagement with the outer surface of a plate member 358,'and that ascrewthreaded member 361- is attached to the other end thereof beyond the plate member 359.

A coil spring 362 is interposed between and secured to the screw-threaded member 361 and the plate member 359, and acts against that plate member and through the medium of the pin 341 and the other plate member 348 to urge both said b members inwardly.

Referring a-gain'to Fig. l0, it will be observed that the element 351 of the sealing device 346 member is disposed in alignment with a `lug 3-61 projecting from the casing. A tension spring 368 islconnected to the lugs 365 and 361 to impartl torque to theI sealing devi-ce 346for maintaining the sealing surface 348 thereof in sliding contact with the drummember 335.

Disposed in sliding engagement with the guide members 344 and the adjacent channel 342 is a substantially cylindrical sealing device 311, Which,'like the sealing device 351 comprises separate elements made. of carbonaceous material adjustably tted together and adapted for rotation about a longitudinally disposed pin 312.

The pin 312 is adapted to be mounted at each end in the respective end plate members 358 and 359 in the manner hereinbefore described in connection with the pin 341 shown in Fig. 12. Coil springs 313 are interposed between the two elements of the sealing device 311 for insuring sealing engagement of the end surfaces thereof with the end plate members. A tension spring 315 is provided for subjecting the sealing device 311 to suicient torque to urge the sealing face 316 `thereof into constant engagement with the drum member 335, one end of the spring being connected to a lug 311 and the other end to a lug element 319 having screw-threaded connection with one of the elements of the sealing device.A

The sealing devices 346 and 31| are adapted to divide the space between the rotary drum mem- -ber 335 andthe wall of the/bore 332 into two compression chambers, indicated generally at 382 and 383 in Fig. 10.

According to this form of the invention, rotatably mounted vane devices 385 are carried by the drum member 335, each of which devices is substantially cylindrical in form and is disposed in sliding engagement Within a suitable channel provided by a 'pair of guide members 386 secured to the drum member by means of screws such as 381. As is best shown in Fig. 11 in the drawings, each vane device 385 comprises two slidably fitted elements 388 and 389, the element 388 having a transversely -disposed groove 390 adapted toareceive a suitably shapedtongue portion 39| formed on the element 389. A coil spring 393 is interposed between the elements for causing the end surfaces thereof to seal against the end plate members 358 and 359, which members are, in

addition, provided with annular recesses containing ring-like c'arbonaceous sealing members 395 and 396, respectively, for insuring against leak.

age of fluid under pressure 4from either of the compression chambers during operation of the compressor.

The drum member 335 is provided with' apertures 400 formed in the hub portion thereof adjacent the respective vane devices 385, through each l of which apertures is disposed a coil spring 40| having one end thereof connected to a lug 402 carried by the adjacent element of the vane device 385 and the other end disposed on a seat por- Each of the and 389 of the sealing device 385, so that possible leakage of the Huid under pressure therepast is prevented.

It will now be understood that the vane devices 385 are relatively oscillated or rotated in periodi'- cally reversing directions through the medium of the drum member 335 and shaft 336 in the .manner hereinbefore explained. .As the vane members 385 are thus moved through the compression chambers 382 and 383, each ofthe longitudinally disposed guide members386 carried by the drummember is adapted to be freely movable into and Aout of the spaces provided'between the corresponding stationary guide members 343 or' 344 and the drum member, so that maximum displacement of fluid is ensured.

Two inlet valve assemblies are provided for controlling the inlet now of air or other fluid to the respective compression chambers. Referring to Fig. 10 of the drawings, the casing 33| has formed thereon a valve portion 4 0 disposed adjacent the compression chamber 382 and a valve portion 4H adjacent the compression chamber 383, each of which valve portions is adapted to contain an inlet valve assembly, which may be of any suitable type and is not shown in detail in the'drawings.

The valve assembly within the valve portion 4|0 is adapted to admit fluid to the compression chamber 382 by way of a passage 4 0a which communicates with the compression chamber at -a point substantially midway of the stroke traversed by the vane device 385. Similarly, the valve mechanism contained in the valve portion 4|| communicates with the compression chamber 383 through central port 4| la. The ports 4,|0a and 4| la are thus adapted to be controlled in accordance with movement of the vane devices 385 for admitting uid to the compression chambers in the same manner as that hereinbefore explained with the embodiment of the invention shown in Fig. 6 of the drawings. s

The casing 332 is also provided with four dis.

charge valve chambers 412, 4I3, 4|4 and 4|5,`

which are arranged radially about the compressor casing and are in communication with an annular manifold discharge passageway 4|6, which is formed in the casing 332 and is connected by way of a passage and pipe 4 I 1 with the usual receiving reservoir, not shown. The valve chambers 4|2 and 4|3 are adapted to communicate with'the compression chamber 382 at the terminal ends thereof by way of passages 4|9 and 420 respectively. A spring pressed valve element 42| is disposed in the valve chamber 4| 2 forcontrolling communication thereto from the compression chamber 382. Similarly, the valve chamber4|3 is provided with a spring pressed valve element 422 which is adapted to control discharge of fluid under pressure from the compression chamber 382 to the valve chamber. Spring pressed valve elements 425 and 426 are likewise mounted in the valve chambers 4|5 and 4|4, respectively, and control communication to said chambers from the compression chamber 383 by way of passages 421 and 428. The discharge valve passages 421 and 428 are connected to the terminal ends of the compressionchamber 383.

Operation of embodiment shoum in Fig. 10

In operation, the compressor 330 functions in substantially the same manner as do the compressors l5 and |58 previously described and illustrated in'Figs. 3 and 6. In Fig. 10 the shaft 336, drum members 335 and vane devices 385 carried thereby are shown in intermediate position. Assuming that the compressor shaft 336 is initially rotated in a clockwise direction, it will readily be understood that the upper vane device 385 is thereby moved toward the sealing member 31| for compressing fluid in the chamber 382, which uid is discharged past the valve element 422 to the discharge passageway 4|6, while at the same time the lower vane device 385 is operated to compress fluid at the leading side thereof within the chamber 383, which fluid under pressure is discharged past the valve element 4|5 to the passageway 4|6 and thence to the receiving reservoir. During this movement of the vane devices 385, the respective inlet valve ports 4l0a and 4| la are uncovered as the sealing surface 406 of the corresponding vane devices are `moved beyond the intermediate position, whereupon air or other fluid is supplied to the portions of the chambers 382 and 383 at the trailing sides of the. two vane devices. Upon completion of the clockwise stroke of the vane devices, the usual oscillating drive mechanism associated with the compressor quickly reverses the direction of rotation of the compressor shaft 338, so that the vane devices' 385 are then moved in a counterclockwise direction through the chambers 382 and 383, thereby effecting supply of fluid under pressure by way of the valve elements 42| and 426 to the discharge passageway 4|8. As thevane devices 385 are thus moved past the inlet valve ports, the inlet valve mechanisms are again operated to supply fluid to the suction portion of each of the compression chambers in preparation for the next clockwise stroke of the vane members.

According to the embodiment of the invention disclosed in Fig. 10, the two sealing devices 346 and 31| controlled by the respective springs 368 and 315, together with the vane devices 385 carried by the drum member and subject to the springs 40|, are thus adapted to be automatically adjusted to compensate for wear during operation of the compressor. Such adjustment for wear in the case of one of the vane devices 385 is illustrated, in somewhat exaggerated form, in Fig. 13 of the drawings.- On the other hand, it is to be expected that, due to the self-lubricating quantities of the carbonaceous material of which the sealing devices and vane devices are composed, wearing thereof will be gradual. The supplyv of oil or other fluid lubricant to the compressor is of course not required.

Conclusion AIt will now be apparent that I have disclosed several embodiment of the invention, in each of which is provided a compressor of compact construction comprising an operating shaft adapted to be oscillated or periodically rotated in alternately reversing directions through a predetermined angle, and self-lubricating lmovable abutments4 or vanes of carbonaceous material operative thereby within arcuate compression chambers for effecting supply of fluid under pressure by way of suitable valve means. By reason of this construction, the compressor operating shaft may be made short and sturdy, and is de-V signed to carry the operating parts such as the vanes in substantially balanced relation in order to reduce possible vibration and noise of operation, while the two varies are adapted to traverse long compression strokes in relation to the areas thereof, so that the load reacting on the bearings member for causing said vane members to compress iiuid within the corresponding compression chambers.

2. In a fluid compressor, in combination, a casing having a substantially circular interior wall, a cylindrical drum memberrotatablymounted in said casing and disposed concentrically of said wall, said drum member having concave guide channels formed longitudinally on opposite sides thereof, sealing means mounted in said casing including members yieldingly engaging said drum member for defining separate compression chambers within said circular wall and end plate means associated therewith for closing the ends of said chambers, inlet and outlet valve means associated therewith, fluid compressing, vane members having convex surfaces complementary to and slidably fitted in said guide channels respectively, said vane members individually comprising a pair of slidably interlocked elements and spring means urging said elements apart for insuring sealing engagement of the end surfaces thereof with said end plate members, means resiliently urging each of said vane members in a rotary direction into sliding engagement with said interior wall of the casing, and driving means operable to oscillate said drum member for causing said vane members to compress fluid within the corresponding compression chambers.

3. In a fluid compressor, in combination, a casing structure having arcuate compression chambers, fluid compressing vane members slid- 'ably mounted in said chambers and operative of the assembly in minimized, As a further feaclaim as new and desire to secure by Letters Patent is:

1. In a fluid compressor, in combination, a casing having a substantially circular interior wall, a cylindrical drum member rotatably mounted in said casing and disposed concentrically of said wall, said drum'member having concave guide channels formed longitudinally on opposite aides thereof, sealing means mounted in said casing and including means yieldingly engaging said drum member for defining separate compression chambers within said circular wall, fluid compressing vane members having convex surfaces complementary to and slidably fitted in said guide channels, respectively, means resiliently urging each of said vane members in a rotary direction for effecting sliding engagement of a portion thereof with said wall, inlet and outlet valve means for said compression chambers, and driving means operable to oscillate said drum ment for constantly rotating said fan meansl to compress fluid, a shaft member journaled in said casing structure concentrically of said chambers and operable to electoscillation of said vane members through said chambers, said shaft member having a longitudinal bore, a rotary motor driven element aligned with said shaft, mechanism cooperative with said element for effecting alternately reversing rotation of said shaft and vane members, fan means operable to produce an air current for cooling the compressor, and a fan shaft journaled within said bore in the rst-named compressor shaft and' operatively connected to said motor driven eleduring operation of the compressor.

4. An air compressor of the type adapted to be driven by a motor 0r the like, comprising a stationary casing structure including a cylindrical portion having a bore and a. single bearing portion disposed concentrically thereof and extending into said cylindrical portion bore, a drive shaft having a free outer end, and an inner end journaled in and supported by said bearing portion, said drive shaft' having the free end thereof disposed outwardly of said bearing portion andV within said cylindrical portion of the casing structure, a hollow drum member secured to said free end of the drive shaft and disposed coaxially of the bore in said cylindrical portion, said drum member being adapted to overhang a part .of said bearing portion, sealing elements resiliently mounted in s'aid cylindrical portion in sliding engagement with said drum membenfor defining a plurality of separate compression chambers within said bore, inlet and outlet valve means for said compression chambers, a plurality of piston vane devices yieldingly mounted on said drum member and respectively disposed in sliding engagement with the walls of said compression chambers, and driving means operable to effect periodically reversing rotation of said drive shaft for causing oscillation of said vane through said chambers.

5. A iluid compressor of the type adapted to be driven by a motor or the like, comprising a casing structure including a cylindrical portion having a bore and having its sole support at one end, a single bearing portion carried concentrically of said cylindrical portion and disposed at least i-n part within said cylindrical portion bore, a. drive shaft having a free outer end, and an inner end journaled in and supported by said bearing portion, said free end extending there-beyond into said bore of said cylindrical portion of the casing, a cylindrical drum member secured to said free end of the drive shaft and having an interior cooling passage, said cooling passage being adapted to receive a partof said bearing portion, re'

devices silient sealing means associated with said cyli-ndrical portion of the casing structure and slidably engaging said drum member for deiining a plurality of separate compression chambers, inlet and discharge valve means for said compression chambers, vane means resiliently mounted on said drum member and respectively disposed in sliding relation with the walls of said compression chambers, and driving means operable to effect periodically reversing rotation of said drum member.

6. A iluid compressor of the type adapted to be driven by a motor or the like, comprising a casing structure including a cylindrical portion having a bore and having its vsole support at one end and a single bearing portion carried concentrically of said cylindrical portion and disposed at least partly within said cylindrical portion bore, a drive shaft having one end journaled in and supported by said bearing portion and having another end extending there-beyond into said bore of said cylindrical portion oi' the casing, a hollow having an interior cooling chamber the peripheral wall of which is adapted to extend in over- 7. In a iiuid compressor: a hollow cylindrical casing structure having a longitudinal bore, a cylindrical drum member of smaller' diameter than that of the bore and rotatably mounted in said casing structure coaxially of said bore, saidv drum member having a relatively thin wallproviding a passageway constructed and arranged to conduct a stream of cooling` air therethrough, means constructed and arranged to define a plurality of compression chambers including a plurality of sealing members operatively mounted in said casing structure and projecting into yielding engagement with said drum member, means eax-4 ried by said casing structure and constituting end walls for said compression chambers, inlet and outlet valves for said chambers, a plurality of vane devices yieldingly mounted in balanced relation on said drum member, said vane devices.

having sliding engagement with the walls of said compression chambers, rotary blower means arranged to force cool air through the passageway in said drum member, and drivingmeans constructed and arranged 'to eiect periodically reversing rotation oi said drum member while causing unidirectional operation of said blower means.

' BURTON S. AIKMAN.

oscillatory motion to the drive 

